I haven't tried the Kode but 30cm fin with a 7.0m seems really small... I use a 32cm fin with a 5.8m... I guess riding style counts a lot, maybe you can get away with it without putting too much pressure on the fin.

I (at 100 kg+) use a similarly sized board, the Exo Cross 106, and use a 30 cm upright fin with a 7 m2 sail. works fine. But for absolute low end performance I have actually used a 40 cm fin as the Cross has a Powerbox. But generally the 30 cm fin is a much better fit (and a 26 cm wavestyle fin for 6.2 and smaller).

As mentioned, a no cam sail would for sure be a better fit for the board, but technically there is nothing that says a cam sail would not work. If you are not super heavy on your back foot, a 30cm US box fin in a sort of upright style would work fine. The Drake crossover 30 is in fact a rather thick profiled fin with excellent bottom end grunt so it should get you up and going rather well.

Personally I often used a 28cm Drake crossover with my 7.0 (on boards like Kode 86, Flare 99 etc).

So you reckon the stock 30cm fin will be OK for a 7.0 at the extreme low end range of the Kode 103? I've been looking for a 34cm US Box and there is not much on the market but found that True Ames do larger US box fins.

What do you reckon is the next logical step down as a smaller fin to use for full power 5.6-5.0 blasting/bump'n'jump/onshore wavesailing? - 28cm or 25cm?

Also what sort of dedicated freestyle fin would bring out the best freestlyle perfromance from the K103?

The reason why I'm asking is that I'm thinking about getting the K103 to cover a big range sails and conditions in New Zealand:
7.0-6.5: Flat water in 12-18knots early planing and speed, harbour blasting and up/down winders, fun slalom racing: 40% of sailing sessions.
6.0-5.6: Powered up bump'n'jump, old school freestyle, very onshore wavesailing and looping: 45% of sailing sessions.
6.0-5.6: Light wind, cross-offshore 'float'n'ride' down the line riding in proper ground swells - Taranaki reef breaks: 5% of sailing sessions.
5.0: High wind bump'n'jump/looping in flat choppy water: 10% of sailing sessions.

I would partner the K103 with my Mistral 84L twinny and Nelson custom 74L twin and 120L Kona Mini Tanker.

So I'm wondering what fins would get the greatest performance and range out of the K103?...

I have the 103,and I recently got a 33cm select Bump and Jump fin, for my 6.5 gator, for that very same reason i.e. to get the most out of the board when its marginal. Thats the biggest I found in US box.

It seems to do the job, i have yet to try in in that configuration when fully powered up, but I had no problem handling the lift with the center strap.

Many things here are imho witnesses about the "mistake" of jumping from us box to tuttle. No strong head for large fins in us, strong head but without easy one back strap option in tuttle. Ugly and slow us system with different sizez and shims to put many times, or time spend sanding heads; useles for not wave boards. Differences also in tuttle boxes
Why refusing thinking also at powerbox in Starboard? Never had a problem with PB.
I know. it's an old story and will not change.
Meanwhile I use to change fin for every different sail, and as I got a bunch of 16 PB fins I cannot think switching to a tuttlebox board, and buy again a lot of fins, even if I would like a lot to have one of such beautiful boards like the Starboards.
Nico from Venice.

P.S. Yesterday I used my 112 litres PB board, back center strap, 40 cm fin, in marginal gusty winds, 8,0 HSM Superfreak. Perfect. It would be too large fin for us, not possible a single strap in tuttle. And therefore no trimming of two screws, less than 30 seconds to fix the PB fin... Nico